Recuperator



s. H. KRYER RECUPERATOR Filed Nov. 5, 1924 2 Sheets-Shee t 1IYL'UGTLIfOr 135. H. Krqy er Flt-T gs.

May 5, 1925.

5. H. KRgaYER RECUPERATOR Filed Nov. 5, 1924 2 Sheets-Sheet 2 PatentedMay 5, 1925.

UNITED STATES SIGURD HJ'ALMAR KROYEB 0] HELLERUP, NEAR, COPENHAGEN,DENMARK.

RECUPERATOR.

Application filed November 5, 1924. Serial No. 747,949.

To all. whom it may concern."

Be it known that I, Sronnn HJALMAR Kngirnn, citizen of the Kingdom ofDenmark, and residing at Hellerup, near Gopenhagen, Denmark, haveinvented certain new and usefulImprovements in Recuperators, of whichthe following is a specification.

This invention relates to a recuperator of that kind having horizontalseries of tubes and around the same channels limited by vertical walls,and in which the horizontal tubes have approximately quadratic crosssection and are so arranged that the plane portions of their walls lieat an angle of with a vertical plane and thateach series of tubesextendsinto the spaces between the tubes of the next series upwards anddownwards. The characterizing feature of the invention is that thehorizontal series of tubes serve to lead the warm combustion gases, thelatter being first led through the uppermost series, then through thenext series and so on downwards, while the channels around thetubesleadthe air through from the bottom upwards in order to preheat it.

In the drawing a construction form of the, invention is represented byway ofexample.

Fig. 1 is a vertical sectional view of the recuperator and a generatorbuilt together, the section being taken on the line BB of Fig. 2. I t

Fig. 2 is a vertical sectional view on line AA of Fig. 1. I

Fig. 3 is a horizontal fragmentary section on the line CC of Fig. 1, and

Fig, 41 is a detail perspective "iew of one of the tubes for the passageof combustion gases.

Referring to the drawing in detail, the smoke or combustion gases of thefurnace heated by gasfrom the generator 0 come from the channel 2' andare led through a plurality of horizontal series of tubes a, passingfirst through the upper series (1,,

c then through the next series (1 and so on until at last having passedthrough the lowermost series a, they ass into the chimney through thechannel a. The plane of section shown in Fig. 2 passes through the tubes(1,, a (1 the arrows indicating the way of the smoke. From the channel2' the smoke passes first from the left to. the right in Fig. 2 throughthe series of tubes (1,, only one of these tubes appearing in Fig. 2.When the combustion gases have passed completely to the right in Fig. 2,they will turn in the so called turning-boxes 9 return fromthe right tothe left in the next lower series of tubes a and thus the smoke is ledback and forth on down through the several series of tubes until itreaches the uptake 7:: to the chimney. In order. to.

and.

guide the smoke from one series of tubes to the next, the turning boxes9, are divided by zigzag partitions r separating to the left in Fig. 2the series a, and a a and (1 ,0 and a so that in the turning-box in theleft hand side of Fig. 2 the connectionis open between the series a anda a, and a and a and a In the right hand turning-box the connections arereversed, which-will easily be understood from the drawing and the aboveexplanation of the path of the smoke.

The air to be preheated in the recuperator is led through the horizontalchannel 6 at the. bottom of the recuperator and leading through one ofthe turnin -boxes 9. The vertical supporting walls (Z or the tubes areprovided with openings u arranged in line with and having the same crosssectional area as the channel I), so that the sucked-in air is allowedto be distributed throughout the. several air channels defined bythewalls (Z. The air rises in zigzag path around the tubes a in order topass as a preheated secondary air through the channel I, m and mix withthe gas comingfrom the generator 0 through the channel a. The mixingtakes place at p.

According to the present invention, the passage of combustion air to bepreheated takes place solely by the natural draught so that this airneed not be sucked through the recuperator. This is of the utmostimportance because it is to be remembered that normally the combustionair coming from the recuperator is led to the fire place of a' generatoror of a furnace where it meets gases produced by a generator. In bothcases the necessary suction of the air through the rccuperator wouldmean also that there. would be a suction through the I draught of airupwards will immediately occur at this place and equalize the differencein temperature.

To enable a portion of the preheated air to be taken out and employed asa primary air in the generator 0 a series of holes 9 are provided in thevertical walls d adjacent one of the lower series of tubes, so that allthe zigzag-shaped air channels in the reeuperators communicate.Furthermore an S-shaped channel 71, leads from these intercommunicatingair channels of the recuperator into the space below the grate t of thegenerator thus enabling a portion of the preheated air to be used asprimary air. The channel it may be closed, or its cross sectional areabe varied, by a valve By thus taking out only a portion of the heatedair the circulation of air around the lowermost series of horizontaltubes becomes more animated, While the quantity of air passing throughthe entire recuperator and leaving it at the top is still sufiieient andmay be regulated in the ordinary way. It is the employment of thenatural draught for causing circulation of the air through therecuperator which enables a portion of the air to be taken out asprimary air. It is already known to preheat the primary air by specialchannels but as the height of the furnace under which the recuperator isplaced will seldom permit the arrangement oi such channels it is'ot thegreatest importance that in such furnaces this invention will allow theprimary air to be preheated.

It will be noted by reference to Fig. 1 that the air to be preheatedwhich passes upwardly through the vertical channels formed by thevertical walls (1 and the latend walls of the recuperator moves in azigzag path owing to the arrangen'ient and shape of the horizontal tubesa. to make the conditions of the draught upwards the best possible andat the same time to expose the air to a maximum of heating surface, thecorners of the tubes are rounded as shown in Fig. 4.

In order.

In order to prevent uninterrupted vertical movement of the heated airalong the side walls of the recuperator, bathe members e are so arrangedwith respect to the outermost tubes of the several horizontal series asto cause such heated air to traverse the same zigzag path as is producedby the arrangement of the tubes relative to one another. I

I claim:

1. A recuperator of the natural. draught type including a plurality ofhorizontal series of tubes, spaced vertical walls, said tubes beingapproximately square in cross section and so arranged that the planeportions of their walls are inclined to the yertical and that the tubesof each series extend into the spaces of the tubes of the adjacentseries, having means for conducting combustion gases into the upperseries of tubes, means for causing the combustion gases to traverse theseveral series of tubes from the upper series to the lower series, andmeans admitting air to the lower por tion of the spaces between thevertical walls externally of the tubes whereby, incident to heating ofthe air, the latter rises in the spaces.

2. A recuperator as claimed in claim 1 characterized by the provision ofmeans permitting the withdrawal of a portion of the heated air at apoint intermediate the upper and lowermost series of tubes.

3. A recuperator of the natural draft type including a plurality ofhorizontal series oi tubes, spaced vertical walls, having meansfoincondueting combustion gases into the upper series of tubes, meansfor causing the combustion gases to traverse the several se-' ries oftubes from the upper series to the lower series, and means for admittingair to the lower portion of the spaces between the vertical wallsexternally of the tubes, whereby incident to heating of the air, thelatter rises in the spaces.

In testimony whereof I affix my signature.

SIGURD HJALMAR KRtOYER.

